Fowl Play Part II -
The Shreveport urban bird experience with art and photography along with information and entertaining stories of backyard birds and nature.

Banner is The Bird That Feel to Earth . Blue Jay photographic art by Rybird

Sunset Woody. Photo of woodpecker by Rybird

Birdsong sounds sweeter because throats filter out messy overtones The purity of birdsong is owed in large part to rapid, controlled changes in the shape of the birds' upper vocal tracts. Riede et al. (2006) showed that songbirds adjust the size and shape of their vocal tract to 'fit' the changing frequency of their song, allowing birds to produce a more whistle-like, pure-tone song. These results support a growing consensus that birds and humans make sound in much the same way although it is presumed these processes evolved independently of each other in birds and hominids. Other studies have implicated tongues, beaks, especially beak gape, in shaping the sound that birds produce. Similarly, humans move their tongues, alter the shape of their upper vocal tracts, and change the shape of their mouths when they sing, laugh, talk and groan."The bird's vocal tract, like the human vocal tract in speech, acts as a resonance filter that can control the sound coming from the mouth," said coauthor
Rod Suthers. "Beak movements during song also contribute to this filter, but are not as important as changes in the size of the internal vocal tract. Human sopranos use the same technique as the cardinal to increase the loudness of very high notes so they can be heard above the orchestra."

Photography of Brown thrashers by Rybird.

Above: Thrashers Present and Past
First there was one Brown Thrasher, a songbird about the size of a mockingbird, that sang every day all day from the tops of the trees. He was calling his mate. She arrived and they built a nest and began raising two little thrashers. Then last week a feral mother cat came like a thief in the night and killed one of the two thrashers so her kittens could have food. The one remaining thrasher continues the care of the nest with the other always in his memory. Photography of Brown thrashers by Rybird.

That birds' throats vibrate when they sing will come as no surprise to birdwatchers. The effect of these oscillations on the birds' sound production, however, was unknown. The acoustics of sound making are complicated. Most tones produced in nature are accompanied by a complex series of higher pitched, quieter tones called overtones. When the loudness of these overtones is high, the tone sounds more complex. Birds can control the loudness of overtones to increase the tonal purity of their song. Humans use a similar technique to produce different vowel sounds of speech by altering the shapes of their throats, the positions of their tongues and the wideness of their mouths.
"At low frequencies, the bird increases the volume of its oropharyngeal cavity and even expands the top of its esophagus," Suthers said. "These air filled structures form a single cavity with a resonant frequency that matches the main frequency of the song. This amplifies the fundamental frequency and suppresses overtones." The shape and total volume (three dimensional space, not loudness) of a singing Northern Cardinal's throat was observed and measured using Xray cinematography to observe and measure the shape and total volume (three dimensional space, not loudness) of a cardinal's throat as it spontaneously sang.
The scientists determined that note changes in birdsong were accompanied by controlled changes in the volume of the upper esophagus as well as the positions of the bird's larynx and hyoid skeleton (a Ushaped bone formation in the bird's throat). They also found that the volume of the upper esophagus goes up whenever the main tone produced by the bird goes down, and vice versa. These alterations of shape have the effect of increasing the main tone and suppressing the loudness of overtones.
From Birdsong sounds sweeter because throats filter out messy overtones at http://newsinfo.iu.edu/news-archive/3214.html

A juvenile male northern cardinal seeks relief from the heat in a water sprinkler I set up for them. They love to get in the tree where they can control how wet they get and feel safe. See more redbirds at Cardinal Delights here on Rybird Music.l

Above: Slide show of various backyard birds taken by Rybird in Shreveport, Louisiana

Family Portrait, a hodgepodge of various bird photographs by Rybird

Below: IOLAIRE SUILE NA GREIN charcoal sketch of eagle by Rybird of Dabble Bird

 Eagle charcoal sketch by Rybird. From the Spartan collection of amateur fine art. See more at Spartan here: http://www.dabblebird.com/spartan.html
The white-tailed eagle is  a magnificent bird. It has the enchanting Gaelic name of Iolaire suile na grein - 'the eagle with the sunlit eye' for its striking, pale eyes.
The white-tailed eagle (Haliaeetus albicilla), is also known as the ern, erne, gray eagle, Eurasian sea eagle and white-tailed sea-eagle. It is a large bird of prey in the family Accipitridae which includes other raptors such as hawks, kites, and harriers. They are found in Eurasia, near large bodies of open water with an abundant food supply and old-growth trees for nesting. They are considered a close cousin of the bald eagle (Haliaeetus leucocephalus).
IOLAIRE SUILE NA GREIN
Eagle, with your sunlit eyes, 
Unfurl your wings, take to the skies
. Great symbol of the true and just,
Imbued with wisdom, strength, and trust.
 High upon the thermals soar,
Embodiment of Nature’s law
. First Nations’ by their will, decree,
You rule the skies with majesty
. In myth, stared down the mighty sun. 
Your voyage of destiny begun
. High above the world you soared,
Your place in legend, firm, assured. 
In clear blue skies, you hold domain,
Great King of Birds, long be your reign.

by nickthegreek ​

The Bird Buddha. Visit Dabblebird.com for my digital art.